Quagga developers and the CERT Coordination Center (CERT/CC) at Carnegie Mellon University announced this week that Quagga 1.2.3 patches several vulnerabilities affecting the BGP daemon (bpgd).

One of the more serious flaws, rated critical by CERT/CC based on its CVSS score, is CVE-2018-5379, a double-free memory corruption issue related to the processing of certain UPDATE messages containing cluster-list or unknown attributes.

“This issue can be triggered by an optional/transitive UPDATE attribute, that all conforming eBGP speakers should pass along. This means this may triggerable in many affected Quagga bgpd processes across a wide area of a network, because of just one UPDATE message,” Quagga developers explained. “This issue could result in a crash of bgpd, or even allow a remote attacker to gain control of an affected bgpd process.”

Another vulnerability, CVE-2018-5381, can be exploited to cause bgpd to enter an infinite loop and stop responding until it’s restarted. “BGP sessions will drop and not be reestablished,” developers said.

Quagga 1.2.3 also patches CVE-2018-5378, a security hole that can lead to sensitive data from the bgpd process being sent over the network to a configured peer. This can also cause the bgpd process to crash.

The last vulnerability patched by the latest Quagga release is CVE-2018-5378, which developers say has “very low” impact.

Linux distributions, including Ubuntu, Debian and Red Hat, have started publishing advisories describing these vulnerabilities. Regarding CVE-2018-5379, Red Hat said “Glibc's heap protection mitigations render this issue more difficult to exploit, though bypasses may still be possible.”

Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.